BSM-PM: New Atom Interferometry Techniques for Long Baseline Quantum Sensing in MAGIS

Stanford University, Stanford CA

Investigators

Abstract

Our understanding of the universe is in some respects highly mature, but in other ways just beginning to unfold. The Standard Model of particle physics has been tested to remarkable accuracy, and yet it can only explain a mere 15% of the matter in the universe. Discovering the nature of the remaining 85% of matter, called “dark matter” because it cannot be directly observed with light, is among the greatest challenges in science. One promising possibility is that dark matter consists of extremely light particles in such high abundance that they collectively act like invisible waves. This so-called ultralight wavelike dark matter is a natural prediction of many theories of physics beyond the Standard Model. Additionally, the recent observation of gravitational waves opens an entirely new modality for studying the universe. Just as it is essential to have many kinds of telescopes to cover different parts of the electromagnetic spectrum, different instruments are needed to maximize our coverage of the gravitational wave spectrum. There is currently a need to fill the gap in the 0.05 Hz to 3 Hz “mid-band” frequency range between what is covered by laser interferometric detectors such as LIGO and the planned LISA spaceborne detector. The mid-band frequency range is promising for detecting gravitational waves produced during the earliest moments of the universe, and could also give astronomers early warning to enable the simultaneous observation of extreme events such as mergers of compact objects like neutron stars and black holes by both gravitational wave detectors and electromagnetic telescopes. To pursue these discovery opportunities, the PIs and collaborators are constructing MAGIS-100, a 100-meter-tall atom interferometer detector located at Fermilab. MAGIS-100 will search for wavelike dark matter and serve as a pathfinder instrument for a future gravitational wave detector. The team of PIs will develop novel techniques at the intersection of atomic physics and quantum information science that will allow MAGIS-100 and future detectors to reach their full scientific potential. This emerging research direction is at the nexus of four fields: particle physics, gravitational wave science, atomic physics, and quantum information science. In addition to mentoring graduate students and postdocs in the MAGIS-100 collaboration, to help them navigate this interdisciplinary research area, the PIs will organize an annual summer school to provide training for both beginning graduate students and more senior researchers in the broader community interested in expanding their expertise on quantum sensing for fundamental physics. Atom interferometers use laser pulses called “atom optics” to split, recombine, and interfere the quantum-mechanical wavefunctions of atoms. The sensitivity of atom interferometer detectors can be increased by using long measurement baselines, analogous to large laser interferometers like LIGO. However, to detect gravitational waves and perform broad searches for dark matter, the signal must additionally be coherently magnified by manipulating the quantum states of the atoms with sequences of thousands of laser pulses. This requires advances beyond current state-of-the-art atom interferometers, which are limited to hundreds of pulses by the accumulation of small errors in each pulse arising from experimental imperfections. To overcome this challenge, the PIs will leverage the framework of quantum control to develop a suite of atom optics techniques for long-baseline atom interferometry that are robust against these errors, addressing several different atom interferometer modalities required by the multi-faceted science goals of MAGIS-100. Long-baseline atom interferometry is a rapidly growing field, and beyond MAGIS these techniques can directly benefit other long-baseline atom interferometers under development around the world, including AION in the UK, MIGA in France, and ZAIGA in China. The team will also work to expand the MAGIS-100 science program by applying these techniques to new types of atoms and to atom interferometer configurations suitable for measurements of the fine structure constant, paving the way for the incorporation of these capabilities into MAGIS-100. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.